Abstract The oxidation mechanism and products of U3Si2 accident tolerant nuclear fuel in flowing air up to 750 °C is reported. Differences between observed and theoretical mass gains for complete oxidation is due to un-oxidised Si that forms nano-crystalline regions of Si. Some Si rich regions are protected by the formation of UO2, which is thermodynamically preferential to oxidise before Si. The UO2 is further kinetically oxidised to form nano-crystalline U3O8. The nanostructure formed, accompanied by large volumetric expansions during oxidation produces pulverisation of fragments into powder, which may have serious consequences for fuel integrity if exposed to oxidative atmospheres.

中文翻译：

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U3Si2容灾核燃料氧化机理研究

摘要 报道了 U3Si2 事故容错核燃料在高达 750 °C 的流动空气中的氧化机理和产物。观察到的和理论的完全氧化质量增加之间的差异是由于未氧化的 Si 形成了 Si 的纳米晶体区域。一些富含 Si 的区域受到 UO2 的保护，UO2 在热力学上优先于 Si 之前氧化。UO2 进一步被动力学氧化以形成纳米晶体 U3O8。形成的纳米结构伴随着氧化过程中的大体积膨胀，将碎片粉碎成粉末，如果暴露在氧化气氛中，这可能对燃料完整性产生严重后果。